Fix attempt to subtract with overflow

Author: forzafedor

src/qrcode/decoder/version.rs

@@ -146,10 +146,10 @@ impl Version {
      *
      * @param dimension dimension in modules
      * @return Version for a QR Code of that dimension
-     * @throws FormatException if dimension is not 1 mod 4
+     * @throws FormatException if dimension is not 1 mod 4 or dimension less than 17
      */
     pub fn getProvisionalVersionForDimension(dimension: u32) -> Result<VersionRef> {
-        if dimension % 4 != 1 {
+        if dimension % 4 != 1 || dimension < 17 {
             return Err(Exceptions::format_with("dimension incorrect"));
         }
         Self::getVersionForNumber((dimension - 17) / 4)

src/qrcode/detector/qrcode_detector.rs

@@ -429,22 +429,30 @@ impl<'a> Detector<'_> {
         let allowance = (allowanceFactor * overallEstModuleSize) as u32;
         let alignmentAreaLeftX = 0.max(estAlignmentX as i32 - allowance as i32) as u32;
         let alignmentAreaRightX = (self.image.getWidth() - 1).min(estAlignmentX + allowance);
-        if ((alignmentAreaRightX - alignmentAreaLeftX) as f32) < overallEstModuleSize * 3.0 {
+        let alignmentAreaWidth = alignmentAreaRightX
+            .checked_sub(alignmentAreaLeftX)
+            .ok_or(Exceptions::NOT_FOUND)?;
+
+        if (alignmentAreaWidth as f32) < overallEstModuleSize * 3.0 {
             return Err(Exceptions::NOT_FOUND);
         }
 
         let alignmentAreaTopY = 0.max(estAlignmentY as i32 - allowance as i32) as u32;
         let alignmentAreaBottomY = (self.image.getHeight() - 1).min(estAlignmentY + allowance);
-        if alignmentAreaBottomY - alignmentAreaTopY < overallEstModuleSize as u32 * 3 {
+        let alignmentAreaHeight = alignmentAreaTopY
+            .checked_sub(alignmentAreaBottomY)
+            .ok_or(Exceptions::NOT_FOUND)?;
+
+        if alignmentAreaHeight < overallEstModuleSize as u32 * 3 {
             return Err(Exceptions::NOT_FOUND);
         }
 
         let mut alignmentFinder = AlignmentPatternFinder::new(
             self.image,
             alignmentAreaLeftX,
             alignmentAreaTopY,
-            alignmentAreaRightX - alignmentAreaLeftX,
-            alignmentAreaBottomY - alignmentAreaTopY,
+            alignmentAreaWidth,
+            alignmentAreaHeight,
             overallEstModuleSize,
             self.resultPointCallback.clone(),
         );